Writing instrument



FIG. 1 is a left side perspective view taken from the front showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left elevational view, the right elevational view being a mirror image thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a top plan view thereof. 

The ornamental design for a “writing instrument”, as shown and described. 